Fluid pressure regulator assemblies for automotive and industrial coating material dispensing systems are known. There are, for example, the systems illustrated and described in U.S. Pat. Nos. Re. 32,151; 2,583,664; 2,806,481; 3,045,691; 3,053,461; 3,150,675; 3,326,228; 3,433,262; 3,828,807; 4,148,932; 4,311,724; 4,348,425; 4,362,124; 4,592,305; 4,660,597; and, 4,828,218. The disclosures of these patents are hereby incorporated herein by reference. No representation is intended by this listing that a complete search of all relevant prior art has been conducted, or that there are no better references than the above listed patents, or that any of the above listed patents is material to patentability. Nor should any such representation be inferred.
Typically, whenever it is necessary or desirable to flush the fluid supply lines to and from such a fluid pressure regulator, the control fluid pressure, for example, compressed air pressure, supplied to a control port of the regulator is increased substantially, increasing the pressure of the flushing fluid, typically, a solvent, used to flush the fluid supply lines. This occurs in an industrial or automotive coating material dispensing setting, for example, when it is desirable to change the color or type of the coating material being dispensed through the fluid pressure regulator. Increasing the pressure of the solvent flowing through the lines increases the speed with which the circuit between a supply of the solvent and a device which dispenses the fluid whose pressure is being regulated is purged and cleaned and readied for dispensing of another fluid whose pressure is to be regulated, for example, a coating material of another color or type. This, in turn, shortens the color change cycle between times when articles stop being coated with a pre-color change color and begin being coated with a post-color change color.
After several color change cycles, the components of the regulator deteriorate and the regulator needs to be serviced. The time between servicings could be extended if it were not necessary to subject the regulator to such high control fluid pressure to get the necessary solvent flow through the fluid supply lines and regulator during solvent flushing.